Improved structural quality and radiative efficiency were observed in GaN thin films
grown by metalorganic chemical vapor deposition on in situ-formed SiN and TiN porous network
templates. The room temperature carrier decay time of 1.86 ns measured for a TiN network sample
is slightly longer than that for a 200 μm-thick high quality freestanding GaN (1.73 ns). The
linewidth of the asymmetric X-Ray diffraction (XRD) (1012) peak decreases considerably with the
use of SiN and TiN layers, indicating the reduction in threading dislocation density. However, no
direct correlation is yet found between the decay times and the XRD linewidths, suggesting that
point defect and impurity related nonradiative centers are the main parameters affecting the lifetime.